Rotary joint

Abstract

A joint structure for transmitting fluid therethrough and having a rotary, hollow sleeve comprised of two sections, each section being journalled in a bushing supported in a stationary casing surrounding the sleeve sections. The adjacent free ends of the sleeve sections are telescopically interfitted for relative axial movement and keyed to each other for unitary rotation. A sealing ring is axially slidably mounted on each sleeve section and urged into engagement with an adjacent sealing surface provided on the housing by forces acting in a direction compressing the sealing rings for providing a rotary joint structure having an extended service life.

I claim: 
     
       1. In a rotary joint for transmitting fluids therethrough, the combination comprising: a. a stationary tubular housing having opposed open ends;   b. an end cap affixed to each opposed open end of said housing, each said end cap having a spherical sealing surface on its inner face and a bearing receiving portion extending outwardly thereof;   c. a rotatable sleeve concentrically journalled within said end caps, said sleeve comprising a pair of axially aligned sections connected together for unitary rotation and axial movement relative to each other within said housing, each said sleeve section extending beyond said spherical sealing surface of said end caps;   d. a bearing disposed within the bearing receiving portion of each said end cap for journalling the end of each of said sleeve section extending beyond said spherical sealing surfaces;   e. a sealing ring mounted for axial movement on each said sleeve section, each said sealing ring having a spherical sealing surface for intimately engaging the adjacent spherical sealing surface on said end caps; and   f. means biasing said sleeve sections and said sealing rings axially apart for urging said sealing rings into sealing engagement with said spherical sealing surfaces on said end caps, wherein said sealing rings are "rigidly" supported by said sleeve sections and the sealing surfaces of said end caps and sealing rings and the forces urging said sealing rings into sealing engagement with said end caps tend to circumferentially compress said sealing rings.   
     
     
       2. A rotary joint as claimed in claim 1, wherein the free end of one sleeve section is counterbored for telescopically receiving the free end of the other said sleeve section, the free ends being keyed together for unitary rotation and axial movement relative to each other. 
     
     
       3. A rotary joint as claimed in claim 2, wherein said means for biasing said sleeve sections apart comprises thrust flanges radially projecting from each said sleeve section adjacent their telescoped ends, said flanges abutting said sealing rings, and a compression spring disposed between said thrust flanges for urging the spherical sealing surfaces on said sealing rings into sealing engagement with the sealing surfaces on said end cap. 
     
     
       4. A rotary joint as claimed in claim 3, wherein each said sealing ring includes a planar sealing surface in abutting sealing engagement with faces on said thrust flanges. 
     
     
       5. A rotary joint as claimed in claim 1, claim 2 or claim 3, including a siphon pipe wherein one of said sleeve sections includes means for receiving and sealingly clamping an end of said siphon pipe thereto for unitary rotation with said sleeve section.